DE 196 18 853 C1 disclosed a motor-driven window lifter with electronic clamping protection, whereby in the flux of force between the drive unit and the window pane there is a prestressed spring with a degressive course. When the prestress force is exceeded, this leads to relative motion of the components that are tensioned to one another, whereby the total stress of the spring is reduced and the clamping force is correspondingly reduced. It is provided that the spring is positioned within an essentially rigid case. The case, which for the purpose of supporting the great prestress force is formed in a comparatively stable way, has a high space requirement that is often not available. In addition, the assembly of the device described requires relatively high resources. The contents of DE 198 52 977.5 are incorporated fully herein by reference.